Thank you Litefoot, I will be having this page open as we put this together tomorrow (or Sunday). At this point I think we might be getting the 125 tank sooner rather than later which makes me happy too. I've been told to start looking so I am. I think the idea is to just do all this once and be done but we'll see. The idea on the hoses is great too I never thought of that.
I'll be happier not having to replace filter media as often as I do and using this FX6 for the 40 gallon, it will be cleaner and I won't have to do filter replacement as often just a cleaning of them.
I swear Link has grown since she got into her 40 gallon, she seems so much bigger already!! She is really loving just floating/treading water and has mastered the art of swimming in reverse and every time she does I hear a back up beeper sound in my head LOL
When I get this new filter set up I might try a bit more water and see how Link takes it, I know she did not like it when I filled the tank more than what level it's at (over half full) so I took water out, Link settled down and I haven't messed around with the water level since. But since she's become a super swimmer and seems more confident in a "real" tank I might see how she reacts - if she flips out, water will be taken out - if she seems good with it water stays.
I'm not going to add anything further into the tank right now (like rocks or driftwood etc) as Link has been through enough changes and I don't want to over stress her. She is still not used to me (my hand yes) so I will wait a few more weeks before doing anything that could upset or stress her out further. I am setting up a "live" food tank in the next week or 2, using one of the old tanks for that and the old Fluval filter but I'm not rushing on that just at the moment.